Give expression in both tuple calculus and domain calculus, Database Management System

Assignment Help:

Consider the following relational schema:
Doctor(DName,Reg_no)
Patient(Pname, Disease)
Assigned_To (Pname,Dname)
Give expression in both Tuple calculus and Domain calculus for every of the queries:
(i) Get the names of patients who are assigned to more than one doctor.
(ii) Get the names of doctors who are treating patients with ‘Polio'.

Ans:
(i)Tuple Calculus:
{p[PName] | p ∈ PATIENT ∧ ∃a1, a2 (a1 ∈ ASSIGNED_TO ∧ a2 ∈ ASSIGNED_TO ∧
p[PName] = a1[PName] ∧ a1[PName] = a2[PName] ∧ a1[DName] ≠ a2[DName])}
Domain Calculus:
{p | ∃p1, d1, p2, d2 ( ∈ PATIENT ∧ ∈ ASSIGNED_TO ∧
ASSIGNED_TO ∧ p1 = p2 ∧ d1 ≠ d2)}
(ii)Tuple Calculus:
{u[Dname] | u ∈ ASSIGNED_TO ∧ ∃t (t ∈ PATIENT ∧ t[Disease] = ‘Polio' ∧
t[PName] = u[PName])}
Domain Calculus:
{d | ∃p1, p2, s2 ( ∈ ASSIGNED_TO ∧ ∈ PATIENT
∧ p1 = p2 ∧ s2 = ‘Polio')}


Related Discussions:- Give expression in both tuple calculus and domain calculus

What is the meaning of recovery, What is the meaning of Recovery? In d...

What is the meaning of Recovery? In deferred update methods, if a transaction fails before arriving its commit point, it will not have altered the database in any way, so UNDO

Describe integrity and security, Describe integrity and security? a)   ...

Describe integrity and security? a)      Domain constraint b)      Referential integrity A value that appears in one relation for a given set of attributes also appear fo

Query by example, Illustrate how you can use QBE to perform logical AND and...

Illustrate how you can use QBE to perform logical AND and OR operation

Determine the method of choosing algorithms, Determine the method of Choosi...

Determine the method of Choosing Algorithms In general, most of operations are easy and have a satisfactory algorithm since description of what is to be done also shows how i

Fragmentation, let us consider a table having 2200 records and the fixed si...

let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation

The transactions, The Transactions- A transaction is definite as the unit o...

The Transactions- A transaction is definite as the unit of work in a database system. Database systems that deal with a huge number of transactions are also termed as transaction p

Determine the strong and weak entity, Determine the Strong and Weak Entity ...

Determine the Strong and Weak Entity Based on the method of foreign key, there might be arise a situation when we have to relate an entity having a primary key of its own and a

What functions does a data dictionary perform, What functions does a data d...

What functions does a data dictionary perform? In a (DBMS)data management system, the principal functions performed by the data dictionary are Management of data defini

Construct an er diagram for a hospital, Construct an ER diagram for a hospi...

Construct an ER diagram for a hospital along with a set of patients and a set of medical doctors Associate with every patient a log of the several tests and examinations conducted.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd